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authorIvan Schreter <schreter@gmx.net>2009-02-21 19:56:50 +0000
committerCarl Eugen Hoyos <cehoyos@rainbow.studorg.tuwien.ac.at>2009-02-21 19:56:50 +0000
commitff6474dd1505411e6875f431379ac4dbb5e45d4a (patch)
tree6184905e8f387f97bee11d905c8093b0a0aa35fd /libavcodec
parent1790a5e908ab98fcf4a81942b751feef67c9e779 (diff)
downloadffmpeg-ff6474dd1505411e6875f431379ac4dbb5e45d4a.tar.gz
Parse NAL units in H264 parser.
Patch by Ivan Schreter, schreter gmx net Originally committed as revision 17488 to svn://svn.ffmpeg.org/ffmpeg/trunk
Diffstat (limited to 'libavcodec')
-rw-r--r--libavcodec/h264_parser.c71
1 files changed, 71 insertions, 0 deletions
diff --git a/libavcodec/h264_parser.c b/libavcodec/h264_parser.c
index a04fd21d51..e00c15bb60 100644
--- a/libavcodec/h264_parser.c
+++ b/libavcodec/h264_parser.c
@@ -27,6 +27,8 @@
#include "parser.h"
#include "h264_parser.h"
+#include "h264data.h"
+#include "golomb.h"
#include <assert.h>
@@ -96,6 +98,73 @@ found:
return i-(state&5);
}
+/*!
+ * Parse NAL units of found picture and decode some basic information.
+ *
+ * @param s parser context.
+ * @param avctx codec context.
+ * @param buf buffer with field/frame data.
+ * @param buf_size size of the buffer.
+ */
+static inline int parse_nal_units(AVCodecParserContext *s,
+ AVCodecContext *avctx,
+ const uint8_t *buf, int buf_size)
+{
+ H264Context *h = s->priv_data;
+ const uint8_t *buf_end = buf + buf_size;
+ unsigned int slice_type;
+ int state;
+ const uint8_t *ptr;
+
+ /* set some sane default values */
+ s->pict_type = FF_I_TYPE;
+
+ h->s.avctx= avctx;
+
+ for(;;) {
+ int src_length, dst_length, consumed;
+ buf = ff_find_start_code(buf, buf_end, &state);
+ if(buf >= buf_end)
+ break;
+ --buf;
+ src_length = buf_end - buf;
+ switch (state & 0x1f) {
+ case NAL_SLICE:
+ case NAL_IDR_SLICE:
+ // Do not walk the whole buffer just to decode slice header
+ if (src_length > 20)
+ src_length = 20;
+ break;
+ }
+ ptr= ff_h264_decode_nal(h, buf, &dst_length, &consumed, src_length);
+ if (ptr==NULL || dst_length < 0)
+ break;
+
+ init_get_bits(&h->s.gb, ptr, 8*dst_length);
+ switch(h->nal_unit_type) {
+ case NAL_SPS:
+ ff_h264_decode_seq_parameter_set(h);
+ break;
+ case NAL_PPS:
+ ff_h264_decode_picture_parameter_set(h, h->s.gb.size_in_bits);
+ break;
+ case NAL_SEI:
+ ff_h264_decode_sei(h);
+ break;
+ case NAL_IDR_SLICE:
+ case NAL_SLICE:
+ get_ue_golomb(&h->s.gb); // skip first_mb_in_slice
+ slice_type = get_ue_golomb_31(&h->s.gb);
+ s->pict_type = golomb_to_pict_type[slice_type % 5];
+ return 0; /* no need to evaluate the rest */
+ }
+ buf += consumed;
+ }
+ /* didn't find a picture! */
+ av_log(h->s.avctx, AV_LOG_ERROR, "missing picture in access unit\n");
+ return -1;
+}
+
static int h264_parse(AVCodecParserContext *s,
AVCodecContext *avctx,
const uint8_t **poutbuf, int *poutbuf_size,
@@ -120,6 +189,8 @@ static int h264_parse(AVCodecParserContext *s,
assert(pc->last_index + next >= 0 );
ff_h264_find_frame_end(h, &pc->buffer[pc->last_index + next], -next); //update state
}
+
+ parse_nal_units(s, avctx, buf, buf_size);
}
*poutbuf = buf;